1. Field of the Invention
This invention relates to apparatus for hingedly and slidably connecting an attachment to a self-propelled mine vehicle and more particularly to a connecting device that hingedly and slidably connects an attachment to the body portion of the mine vehicle to permit the attachment to pivot and to move upwardly and downwardly and thereby remain in slidable contact with the mine floor independent of the movement of the vehicle body portion as it travels over the undulating surface of the mine floor.
2. Description of the Prior Art
Self-propelled haulage vehicles, such as shuttle cars, are used in mines for transporting dislodged material from a mining or loading machine out of the mine. The shuttle car includes a longitudinally extending compartment in which the mined material is loaded and after loading the shuttle car moves from an area adjacent the mine face to a fixed haulage system such as an endless conveyor where the coal is discharged from the shuttle car onto a conveyor belt.
The shuttle car is controlled from an operator's compartment that is rigidly secured to the sidewall of the vehicle. An example of such arrangement is disclosed in U.S. Pat. No. 3,067,830. Suitable controls are provided on the operator's compartment by which the operator controls the movement of the vehicle between the mine face and the discharge point. Also, operation of the conveyor in the haulage compartment is controlled from the operator's compartment.
The machine operator in the operator's compartment is exposed to the mine roof and is, therefore, subject to serious injury from falling debris. Mine safety requirements now require that the machine operator be protected from overhead debris falling from the mine roof. Thus it has become the practice to utilize overhead canopies for protecting operators of various equipment in a mine from the hazard of roof falls. For a shuttle car, however, the limited overhead clearance of the operator's compartment hinders the installation of the canopy particularly when the car is operated in a mine seam having a height of less than 40 inches. With the operator's compartment fixed on the vehicle and raised above the mine floor to provide the necessary ground clearance between the bottom of the compartment and the mine roof, there is insufficient clearance above the top of the shuttle car for the installation of an overhead protective canopy. Furthermore, when there is little clearance between the top of the canopy and the mine roof, the canopy will strike the mine roof as the shuttle car moves upwardly and downwardly as it travels over the undulating surface of the mine floor.
U.S. Pat. No. 4,022,026 discloses a machine used in coal mines with a pivotally supported canopy over an operator's station for protecting a machine operator from falling debris. The canopy is pivotally connected at one end to the machine body portion for limited upward movement toward the mine roof. The opposite or free end of the canopy is connected to the free end of a platform by a pair of hydraulic jacks. The platform, in turn, is pivotally connected at the other end to the machine body portion. The free end of the platform is supported from the canopy by the pair of hydraulic jacks. When the jacks are in a retracted position, the free end of the platform is spaced from the mine floor. When it is desired to move the canopy into abutting relation with the mine roof, the jacks are extended to move the free end of the platform into abutting relation with the mine floor and the free end of the canopy into abutting relation with the mine roof. The canopy thus provides roof support for the operator positioned on the platform. It is stated that the free end of the platform can remain in abutting relation with the mine floor when the machine is stationary or moved for short distances. It is, however, believed that the apparatus disclosed with the free end of the platform in contact with the mine floor is not suitable for vehicles that travel long distances over an undulating surface and an undesirable plowing action would occur between the free end of the platform and the mine floor when the platform is moved rearwardly with the machine.
U.S. Pat. No. 4,078,629 discloses an operator's compartment having a bottom portion positioned to rest entirely upon the mine floor and slide along the surface of the mine floor as the haulage vehicle is propelled. The operator's compartment is slidably supported on a sidewall of the vehicle to move upwardly and downwardly independently of the upward and downward movement of the vehicle as it travels over the uneven surface of the mine floor. With this arrangement the additional overhead clearance necessary to install a canopy above the compartment is provided by positioning the compartment for slidable movement on the mine floor.
It is also known to pivotally connect the front end portion of a canopied operator's compartment to a mining machine with the rear end portion resting on the mine floor. With this arrangement the rear end portion drags on the mine floor as the mining machine advances in the mine entry. When the mining machine advances, the front end of the machine tends to dip downwardly raising the rear end of the machine. With the pivotal arrangement the compartment rear end portion remains on the mine floor so that the canopy does not strike the mine roof. The front end of the operator's compartment is, however, connected to the mining machine so that the upward and downward movement of the mining machine is transmitted to the operator's compartment through the pivot connection. The canopy may be vertically fixed to extend a preselected height above the operator's compartment.
While it has been suggested by the prior art devices to pivotally connect an operator's station to the body portion of a self-propelled mine vehicle and to slidably connect an operator's compartment to the vehicle mobile body portion for upward and downward movement relative thereto so that the compartment may remain in slidable contact with the mine floor as the vehicle is advanced, there is need for a connecting device that is operable to secure an attachment, such as a roof drilling and bolting unit and the like, to the body of a self-propelled mine vehicle to permit the attachment to remain in slidable contact with the mine floor. However, the connection between the attachment and the vehicle body must permit the attachment to move independently of the vehicle body to remain in contact with the mine floor as the vehicle travels over the undulating surface of the mine floor.